This invention relates generally to a refrigerant recovery apparatus used for removing, purifying and recycling refrigerant from refrigerant systems. More particularly, the invention relates to such an apparatus adapted for use with refrigerant systems commonly known as chillers, which operate at negative pressure, such that when leaks occur non-condensable atmospheric gases are drawn into the system, the non-condensable gases reducing the efficiency of the chillers to the point that the non-condensable gases must be separated from the refrigerant gases by a purger system. Even more particularly, the invention relates to an apparatus incorporating a recovery tank coupled with a slow, high efficiency purger to further separate the refrigerant gases from the non-condensable gases after initial treatment by fast, low efficiency purger systems, capable of receiving gases from a plural number of refrigerant chiller systems, as well as capable of withdrawing both liquid refrigerant and refrigerant gas from the refrigerant chiller systems.
Refrigerant chiller systems comprising a system for utilizing compressible refrigerant gases, for example CFC, to remove heat from the air, are well known for use in large buildings. For any relatively large building, a number of individual refrigerant chillers will be needed. The chiller systems operate at below atmospheric pressure, so that any leaks occurring in the system result in non-condensable atmospheric air being drawn into the system. This reduces the efficiency of the system and will eventually prevent the chiller systems from performing their function, unless the non-condensable gases are periodically removed from the system. It is known to use purger systems permanently connected to the chillers to separate the refrigerant gas from the non-condensable gases, the refrigerant gas undergoing a phase change into the liquid form in the presence of cooling coils contained within the purger. The non-condensable gases remaining in the gaseous state are then typically vented to atmosphere. Because of time and cost considerations, the purgers used with chillers are relatively fast, but low efficiency purgers, the cooling coils operating in the 35 to 80 degree Fahrenheit temperature range. This results in the bulk of the refrigerant gas being separated from the non-condensable gases, but the gas vented to atmosphere still contains a relatively large component of harmful refrigerant gas. As the pollution problem grows, stricter emission standards are being implemented, to the point that the standard low efficiency purgers do not remove enough of the refrigerant gases to satisfy the requirements.
There exist high efficiency purgers which operate at temperatures in the area of zero degrees Fahrenheit, but these purgers are slow in operation and relatively costly, to the point that equipping each refrigerant chiller system is not a practical solution to the problem. To prevent the venting of refrigerant gas to the atmosphere along with the non-condensable gases, a refrigerant recovery apparatus has been developed which can be interconnected with any number of refrigerant chiller systems and low efficiency purgers, the refrigerant recovery apparatus having a large capacity recovery tank containing cooling coils for initial separation and a slow, but high efficiency purger to dramatically reduce the amount of residual refrigerant gas mixed with the non-condensable gases prior to venting to atmosphere.
It is an object of this invention to provide a refrigerant recovery apparatus with a slow, high efficiency purger, which can be utilized with any number of refrigerant chiller systems having fast, low efficiency purgers, to separate the harmful refrigerant gas from the non-condensable gases prior to venting to atmosphere.
It is a further object of the invention to provide such an apparatus that takes the output gas from the low efficiency purgers and further purifies it by separating out up to 90 percent of the refrigerant gas remaining in the output gas prior to venting to atmosphere.
It is a further object of the invention to provide such a apparatus that operates automatically and does not interfere with the normal purging cycles of the individual refrigerant chiller systems.
It is a further object to provide such a system which allows also remove and replace liquid refrigerant and refrigerant gas the recovered refrigerant, now in liquid form, to be recycled back into the refrigerant chiller systems.
It is a further object to provide such a system which can directly from the refrigerant chiller systems.